Duma's Method - Practice Questions & MCQ

The nitrogen containing organic compound, when heated with copper oxide in an atmosphere of carbon dioxide, yields free nitrogen in addition to carbon dioxide and water.

Traces of nitrogen oxides formed, if any, are reduced to nitrogen by passing the gaseous mixture over a heated copper gauze. The mixture of gases so produced is collected over an aqueous solution of potassium hydroxide which absorbs carbon dioxide. Nitrogen is collected in the upper part of the graduated tube as shown in the figure.
Let the mass of organic compound = mg
Volume of nitrogen collected = V₁ mL
Room temperature = T₁K

Where p₁ and V₁ are the pressure and volume of nitrogen, p₁ is different from the atmospheric pressure at which nitrogen gas is collected. The value of p₁ is obtained by the relation;
p₁ = Atmospheric pressure – Aqueous tension
22400 mL N₂ at STP weighs 28g.